THE following letter to Mr. Darwin has been forwarded to us by him
for publication:—

"Museum, Auckland, October 23, 1877

"My Dear Sir,—I forward to you a copy of a paper on the
fertilisation of Selliera, one of the Goodeniaceæ,
which perhaps you may care to glance over. When I wrote it I did not
know of your notes on Leschenaultia, published in the Gardener's
Chronicle for 1871. In both plants the pollen is shed before the
expansion of the flower, and neatly collected in the indusium, but in Selliera the stigma is situated within the indusium, and by its gradual upward
growth after the flower expands slowly forces out the pollen, which is
then transferred by insects to older

flowers. When mature, the stigma protrudes considerably beyond the
indusium. This appears to differ entirely from what takes place in Leschenaultia.

"I have recently been much interested with the curious irritability
displayed by the stigma of Glossostigma elatinoides, one of
the Scrophularineæ. The style is dilated towards its apex into a broad
spoon-shaped stigma, which, when the flower expands, is closely doubled
over the four stamens, entirely concealing them from view. If the front
of the bent part of the style is touched it at once springs up,
uncovering the stamens, and moves back to the upper lobe of the
corolla, to which it becomes closely applied. In this position it
remains for a few minutes, and then slowly moves back to the stamens
and curves over them as at first. It appears to me that this
irritability of the stigma is simply a contrivance to insure
cross-fertilisation, for an insect crawling into the flower must
inevitably touch the stigma, which would then uncover the stamens. On
withdrawing, the insect would be certain to dust itself with pollen,
but it would not by this effect the fertilisation of the flower, for
the stigma would be then closely applied to the upper lobe of the
corolla, entirely out of its way. If the insect were, however, to visit
another flower it is evident that it must come into contact with the
stigma at its first entrance and would doubtless leave some pollen
thereon. The movement of the stigma is remarkably rapid, and its apex
must pass through an angle of at least 180o. I have been
unable to find a record of a similar case, or of so pronounced a degree
of irritability in the stigma of any plant. The movement of the lobes
of the stigma in Mimulus is much weaker, and is through a
much less angle.